(2) In programming, the natural data size of a computer. The size of a word varies from one computer to another, depending on the CPU. For computers with a 16-bit CPU, a word is 16 bits (2 bytes). On large mainframes, a word can be as long as 64 bits (8 bytes).

Some computers and programming languages distinguish between shortwords and longwords. A shortword is usually 2 bytes long, while a longword is 4 bytes.